<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think\db\builder;

use think\db\Builder;

/**
 * Sqlsrv数据库驱动
 */
class Sqlsrv extends Builder
{
    protected $selectSql = 'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%) AS thinkphp) AS T1 %LIMIT%%COMMENT%';

    /**
     * order分析
     * @access protected
     * @param mixed $order
     * @return string
     */
    protected function parseOrder($order)
    {
        return !empty($order) ? ' ORDER BY ' . $order : ' ORDER BY rand()';
    }

    /**
     * 随机排序
     * @access protected
     * @return string
     */
    protected function parseRand()
    {
        return 'rand()';
    }

    /**
     * 字段名分析
     * @access protected
     * @param string $key
     * @return string
     */
    protected function parseKey($key)
    {
        $key = trim($key);
        if (!is_numeric($key) && !preg_match('/[,\'\"\*\(\)\[.\s]/', $key)) {
            $key = '[' . $key . ']';
        }
        return $key;
    }

    /**
     * limit
     * @access protected
     * @param mixed $limit
     * @return string
     */
    protected function parseLimit($limit)
    {
        if (empty($limit)) {
            return '';
        }

        $limit = explode(',', $limit);
        if (count($limit) > 1) {
            $limitStr = '(T1.ROW_NUMBER BETWEEN ' . $limit[0] . ' + 1 AND ' . $limit[0] . ' + ' . $limit[1] . ')';
        } else {
            $limitStr = '(T1.ROW_NUMBER BETWEEN 1 AND ' . $limit[0] . ")";
        }
        return 'WHERE ' . $limitStr;
    }
 /**
     * 生成update SQL
     * @access public
     * @param array $fields 数据
     * @param array $options 表达式
     * @return string
     */
    public function update($data, $options)
    {
        $table = $this->parseTable($options['table']);
        $data  = $this->parseData($data, $options);
        if (empty($data)) {
            return '';
        }
        foreach ($data as $key => $val) {
            $set[] = $key . '=' . $val;
        }

        $sql = str_replace(
            ['%TABLE%', '%SET%', '%JOIN%', '%WHERE%', '%ORDER%', '%LIMIT%', '%LOCK%', '%COMMENT%'],
            [
                $this->parseTable($options['table']),
                implode(',', $set),
                $this->parseJoin($options['join']),
                $this->parseWhere($options['where'], $options['table']),
                '',
                $this->parseLimit($options['limit']),
                $this->parseLimit($options['lock']),
                $this->parseComment($options['comment']),
            ], $this->updateSql);

        return $sql;
    }
}